Glaucoma refers to a group of diseases that can damage the optic nerve of the eye and consequently may cause blindness or visual impairment. Glaucoma is one of the major causes of blindness and one of the leading causes of preventable blindness. Typically, glaucoma is characterized by noticeable changes in the optic nerve, sometimes associated with high or elevated intraocular pressure (TOP) and loss of peripheral vision. TOP above the normal physiological range (i.e., typically greater than 21 mmHg), may optionally be a sign of improper drainage of intraocular fluid (e.g., aqueous humor), which is normally produced at a rate of 2.5 ml/minute (i.e., this production rate typically varies among individuals). A rise in intraocular pressure, subjects the optic nerve to a pressure, referred to as the cupping of the optic disc. This condition is called glaucoma. Glaucoma does not usually cause pain, does not affect the central vision, and it is not detected by the patient, at least at an early stage, when proper treatment may optionally be prescribed, to prevent progress to an advanced stage.
Research indicates that possible causes of glaucoma may be an excessive release of pigmentation, a build up of proteins or other chemicals, the flaking of the iris or other tissues (e.g., ciliary bodies) and the like. These conditions, such as the excessive release of pigmentation lead to blockage of the trabecular meshwork, thereby preventing proper drainage of the aqueous humor from the eye. When the blockage is severe, aqueous humor accumulates in the anterior and posterior chamber, thereby increasing IOP. High IOP reduces blood flow to the eye and increases the hydraulic pressure on the optic nerve. The increased pressure may progressively interrupt the metabolic processes of cells in the optic nerve and consequently lead to a progressive destruction of the optic nerve. The outcome is permanent damage to the optic nerve, which causes degeneration of vision and eventually, to complete loss of vision.